Rotors for helicopter



FIG. 1 is a side elevation view of rotors for a helicopter; showing our new design;

FIG. 2 is an elevation of the side opposite that shown in FIG. 1;

FIG. 3 is a top perspective view thereof; and,

FIG. 4 is a top perspective view of the end opposite that shown in FIG. 3.

Broken lines are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for rotors for helicopter, as shown and described. 